Valve sleeve for internal-combustion engines



Patented Feb. 25, 1930 UNITED STATES ATENT orrios HENRY J. EDWARDS, OF TOLEDO, OHIO, ASSIGNOR TO THE WILLYS-OVERLAND COM- IPANY, 0F TOLEDO, OHIO, A CORPORATION OF OHIO VALVE SLEEVE FOR INTERNAL-COMBUSTION ENGINES No Drawing.

,which the relative friction of the sleeves is reduced by a proper selection of materials.

Another object of the invention is to provide an internal combustion engine with a pair of co-acting steel valve sleeves in which 7 the tendency of the sleeves to score or weld together is reduced by the use in one sleeve of steel having a different carbon content i'rom that in the other. The use of steel sleeves in sleeve valve enin sleeve weight, and also by permitting the use of lighter sleeve driving parts.

Much trouble has been experienced heretofore with steel sleeves because of their well known tendency to score which is an eX- pression used in the art to denote the destruction of the finished sleeve surface by the welding action of those portions of the sleeves which intimately contact, through temporary destruction of the oil. film. The scoring is cumulative in its action and causes seizing. The efforts of the engine designers in endeavoring to overcome the difficulty have heretofore been directed toward preventing the like metallic surfacesfrom contacting, usually by the interposition of another metal, such as Babbitt, between the adjacent steel surfaces of the sleeves.

It has long been supposed that this aflinity of the steel surfaces was inherent in the metal and that the conventional cast iron sleevesv 7 would score, if it were not for the free Application filed April 14,

1926. Serial No. 102,075.

a It is commonly known that two hardened steel parts, or one soft and one hardened part could be satisfactorily used as co-actingbearing combinations, but the distortion which takes place during the hardening treatment makes these combinations impractical for thin sleeves. It was supposed that the satisfactory result obtained from such combinations in other bearings was due to the physical hardness of one or both of the mating parts. That theory I believe to have been an incorrect one. My experiments have demonstrated, on the contrary, that the phenomenon is due to the high combined carbon contentof the steel composing at least one of the sleeves, and is not dependent on the heat treatment. This discovery allows the use of thin sleeves, one of which has a very high com bined carbon content, preferably 1% or more, although .70 to 80% is satisfactory. No hardeningtreatment isnecessary to the satisfactory functioning of sleeves made from this steel and they may be made cheaply because no allowance need'be made for the correction of distortion. In order to take full advantage of the benefits of the discovery, I prefer to constructone sleeve of a steel having an extremely high combined carbon content, say 1% or higher and the mating sleeve of any commercial low carbon steel such as .10 to, 20% carbon. This combination has been found to be the most suitable selection of metals and permits one of the sleeves to be formed of a relatively cheap material. Both sleeves may be used in substantially the same physical condition as when received from the mill, and will normally have a shore hardness of 45 or less. It is not necessary that the sleeve having the high carbon content, be composed of a homogeneous material, as a sleeve having the desired proportion of carbon at the surface and a much lower carbon content beneath the surface, will function in the same manner as a sleeve having the same proportion of carbon throughout its section.

lVhile I have described somewhat in detail certain embodiments of my invention, it is to be understood that this description is illustrative only and that I do not regard the invention as limited to the details of construchis tion described except in so far as I have included such limitations Within the terms of the following claims.

I claim as my invention:

1. In an internal combustion engine of the sleeve valve type the combination of a pair of unhardened steel valve sleeves, one of which has a combined carbon content of more than twice that of the other sleeve.

2. In an internal combustion engine; the combination of a pair of unhardened co-acting valve sleeves, one of said sleeves having a combined carbon content greater than .70% and the other of said sleeves having a carbon content of less than 30%. I

3. In an internal combustion engine the combination of a pair of co-acting steel valve sleeves, one of Which has a combined carbon content greater than 57 0%, the other'of-vvhich has a combined carbon content of less than .30 and both of said sleeves having a Shore hardness less than 45.

r 4; In an internal combustion engine of the sleeve valve type, a pair of reciprocating steel sleeves, said sleeves being formed of steel compositions of unlike combined carbon content;

5. In an internal combustion engine of the sleeve valve type, a pair of reciprocating steel sleeves, the composition of said sleeve surfaces contacting with each other being of unlike combined carbon content.

6'. In an internal combustion engine of the sleeve valve type, a pair of reciprocating sleeves 'formed of steel of unlike'combined carbon composition, one of said sleeves having a combined carbon content of more than ;70%', and the'other sleeve having a combined carbon content less than that of the first mentioned sleeve.

In testimony whereof, I afiix my signature.

HENRY J. EDWARDS. 

